pyrrolizidine

pyrrolizidine

a specific chemical configuration which is common to a number of naturally occurring compounds called the pyrrolizidine alkaloids. Common plant sources are in the genera Crotalaria, Echium, Heliotropium, Senecio.

pyrrolizidine alkaloidosis

the disease caused by poisoning with pyrrolizidine alkaloids. The hepatic lesion tends to be chronic and is characterized by necrosis, megalocytosis of hepatocytes due to inhibition of mitosis, biliary ductule, proliferation, vasculitis and perivenous fibrosis. Lesions are most severe in the liver and result in the syndrome of jaundice, photosensitization and hepatic encephalopathy. Some alkaloids cause lung damage characterized by edema, fibrosis, alveolar epithelialization and emphysema, e.g. jaagsiekte. Megalocytosis also occurs in the kidney and there may be extensive nephrosis. There may also be ulceration of the mucosa of the esophagus, stomach and intestines and carcinogenesis is a feature in some animals. An incidental pathogenesis is a concurrent chronic copper poisoning causing the disease toxemic jaundice.

Background: Because of the hepatotoxic, mutagenic, and cancerogenic effects of pyrrolizidine alkaloids (PAs) the German Federal Institute for Risk Assessment (BfR) recommends not to exceed a daily PA intake of 0.

For instance, pheromone production in males has been determined to directly depend on their diet as caterpillars, and only occurs when the diet contains Crotalaria pyrrolizidine alkaloids (PAs) (conner et al.

In 1992 the Commonwealth Drugs and Poisons Scheduling Standing Committee (now National Drugs and Poisons Schedule Committee) scheduled a number of herbs containing pyrrolizidine alkaloids, restricting the use of such herbs as Borago off, Pulmonaria spp, Senecio spp, Tussilago farfara and Symphytum off (which, based on lack of scientific evidence, was later rescheduled to allow its use topically).

The various ailments for which searches are going on in plants for newer drugs are too numerous to mention; to cite just a few examples, new plant-derived compounds are being searched for treatment of malaria because of the increasing resistance of Plasmodium falciparum against currently available anti-malarial drugs (Batista, et al, 2009; Kihampa, et al, 2009), searches for anti-fungal, molluscicidal and larvicidal compounds in African medicinal plants has been reviewed by Marston et al (1993), anti-leishmanial activity in Israeli plants has been reviewed by El-On et al (2009), and anti-trypanosomal and cytotoxic activities of pyrrolizidine alkaloid-producing plants of Ethiopia has been reported by Nibret et al (2009).

Some specific topics covered include plant-herbivore interaction, hydrocarbons and insects' social physiology, addiction to pyrrolizidine alkaloids in male Danaine butterflies, and physiology related to choices in feeding, mating, and oviposition.

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